Cutter and bearing assembly



Feb. 13, 1940. R. w. MAXWELL 2,190,365

CUTTER AND BEARING ASSEMBLY FiledJan. 24, 1938 Patented Feb. 1'3, 1940 UNITED STATES 2,180,365 cU'rrna AND BEARING ASSEMBLY Robert W. Maxwell, hos Angelea CaliL, alaignor to Globe Oil Tools Company, Los Nietos, Calif.,

a corporation of California Application January 24, ms, Serial No. mean 4 Claims.

This invention relates to well drilling tools and relates more particularly to a roller cutter for a drilling tool and bearing means for the cutter. A general object of this invention is to provide 5 a simple, practical and dependable roller cutter and bearing assembly that is easy and convenient to handle.

Another object of this invention is to provide a roller cutter and bearing assembly that may be handled, transported and installed on the tool as a unit. 1

Another object of this invention is to provide a cutter and anti-friction bearing assembly embodying a simple, inexpensive retaining member that may be inserted in the pin receiving openings of the bearing elements at the place of manufacture to hold the bearing elements against separation and movement, so that the assembly may be conveniently handled as a unit and quickly installed on the bit or drilling tool.

A further object of this invention is to provide a cutter and bearing assembly of the character mentioned in which the retaining member holds the bearing elements against relative turning so that the elements may be more readily secured or welded to the bit body in their proper positions.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of my invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. l is a' vertical detailed sectional view of a rock bit illustrating two cutter and bearing as- 36 semblies of the character provided by theinvention. Fig. 2 is an enlarged fragmentary vertical detailed sectional view of one of the cutter and bearing assemblies of the bit and adjacent parts of the bit body. Fig. 3 is an enlarged perspec- 40 tive view of the retaining member of one of the assemblies, and Fig. 4 is a fragmentary transverse detailed sectional view taken as indicated by line 4-4 on Fig. 2.

The present invention may be embodied in cutter and bearing assemblies for use on well drilling tools of various characters. In the following detailed disclosure I-will describe a typical form of the invention incorporated in a rock bit for use in the rotary method of well drilling. It is to be understood that the invention is not to be construed as limited or restricted to the form or application of the invention about to be described, but is to be taken as including any features or modifications that may fall within 66 the scope of the claims.

The rock bit illustrated in the drawing comprises a body It provided at its upper end with a tapered screw threaded pin II for facilitating the connection of the bit with the drilling string.

Two diametrically opposite downwardly and out- I I wardly projecting legs l2 are provided on the lower end of the body ill. The legs l2 have downwardly and outwardly inclined bearing-surfaces l3 on their inner sides and the lower ends it of the legs i2 are preferably fiat and at substanl0 tially right angles to the surfaces l3. A substantially central web 15 projects from the lower end of the body ill in spaced relation to the legs l2. The web I5 has downwardly and outwardly inclined wings i6 whose outer surfaces I! are fln- 15 ished and parallel with the surfaces i3. The lower ends l8 of the wings ii are preferably flat and at right angles to the surfaces H. The web l5 carries a shaft or pin IQ for supporting the inner roller cutters 20. The outer roller cutters C, embodied in the assemblies of the invention to be hereinafter described, are arranged between the legs l2 and the wings It. A fluid passage 2i enters the body ill from the upper end of its pin II and discharge ports 22 communicate with u the lower end of the passage 2| and direct the circulation fluid downwardly against the cutters of the bit. The assemblies of the outer cutters C and their bearing means are identical and I will proceed with a detailed description of one 30 assembly, it being understood that such description is equally applicable to the other assembly.

The improved cutter and bearing assembly of the present invention comprises a cutter C having a central longitudinal opening 23, a plurala ity of bushing or bearing elements A and B in the cutter opening 23, balls 24 rotatably supporting the cutter C on the bearing elements A and B and a retaining member 25 for holding the bearing elements A and B against separation and 0 relative movement. I

The cutter C is in the nature of a roller cutter and in the particular embodiment of the invention illustrated is generally frusto-conical in shape. The opposite ends of the cutter C are flat and parallel and the periphery of the cutter is provided with suitable cutting teeth 26. The outer corners 21 .of the teeth 26 are preferably beveled ofl.

The bearingelements A and Bare arranged in o the opening 23 of the cutter C and are adapted to be attached to and supported on the body Ill of the bit. In the particular form of the invention illustrated in the drawing there are two bearing elements A and B, the element A being as located in the outer portion of the cutter opening 23 and the eleme'ntB being arranged in the inner portion of the opening 23. The elements A and B are spool like parts and have central longitudinal openings 23 and flat parallel opposite ends. The two elements A and B are arranged in end to end relation with their inner ends in abutment. The outer end of the bearing element A is adapted to cooperate with the bearing surface l3 of a body leg l2, while the outer end of the element B is adapted to cooperate with the surface H of a wing 3. A lug 23 is provided on the outer end of the bearing element A to project below the lower end H of the addacent leg l2. to be secured thereto by welding v33. The welding 38 aids in securing the bearing element A to the body leg l2 and prevents rotation of the bearing element during operation of the bit. A lug 3| is provided on the outer side of the bearing element B to project at or below the lower end 3 of the adjacent wing l3 and is secured to the lower end of the wing by welding 32. The welding 32 aids in securing the bearing element B to the wing l3 and prevents tumlng of the bearing element during operation of the tool. o

The balls 24 are provided to rotatably support the roller cutter C on the bearing elements A and B. There are two axially spaced ball grooves or races 33 provided in the wall of the cutter opening 23. The periphery of the bearing element A is provided with a ball race 34 opposing one of the races 33 and the periphery of the bearing element B has an annular ball race 35 opposing the other race 33. The balls 24 are arranged in the sets or pairs of opposing races 33 and 34 and 33 and 35 to support the cutter C for free rotation.

The race 34 faces axially toward the adjacent wing l6 as well as outwardly, and the race 35 faces axially toward the adjacent leg l2, as well as outwardly. The races 33 in the cutter opening 23 are of substantial depth so that the balls 24 cooperating with the deep races 33 and the diagonal or pitched races 34 and 35 are operable to transmit the axial thrusts as well as the radial thrusts that are imposed on. the cutter C, that is, the balls 24 in the set of races 33 and 34 are adapted to take the outward end thrusts as well as the radial thrusts, while the balls 24 in the set of races 33 and 35 areadapted to take the inward end thrusts as well as the radial thrusts. It will be observed that the balls 24 cooperating with the pairs of races 33 and 34 and 33 and 35 formed and related as described above, prevent displacement of the cutter C from the assembly of the elements A and B. The cutter C is supported solely or entirely by the series of balls 24 and does not bear on the adjacent leg l2 or the adjacent wing l3.

The retaining member 25 is an important feature of the invention. The member 25 serves to hold the bearing elements A and B against separation prior to the mounting of the cutter and bearing assembly on the bit so that the said assembly may be conveniently handled, transported and installed as a unit. The member 23 also serves to hold the bearing elements A and B against relative turning. so that the arrangement of either the element A or the element B with its lug 23 or 3| in position for welding to the leg l2 or the wing l6, as the case may be, automatically positions the other element A or B in the right position for welding. I

The member 25 is a simple inexpensive part formed of steel or other material having the desired flexibility and resiliency. The member 25 is arranged in the aligned longitudinal openings 28 of the bearing elements A and B and is of suf flcient length to have its opposite ends at or adjacent the outerends of the elements. The member 25 is tubular and preferably has a thin wall 5 to be flexible and to occupy a minimum of space in the openings 28. The retaining member 25 is provided with a longitudinal split or slit 33 extending from one end to the other. The slit 33 renders the member 25 contractible and expansible. The opposite end portions of the member 25 are flared to have holding cooperation with the bearing elements A and B. An inclined and outwardly projecting annular flange '31 is provided on each end of the member 25. The flanges l 31 are preferably identical andintegral parts of the member 25.

The bearing elements A and B are shaped to receive or. cooperate with the flanges 31 of the member 25. Annular depressions or sockets 33 are provided in the outer ends of the members A and B at the mouths of their openings 28. The walls of the sockets 38 slope inwardly toward the center of the cutter and bearing assemblies to conform to and properly receive the flanges 31. a The sockets 38 and the'flanges 31 are related so that the flanges may be entirely received in the sockets so that the outer margins of the flanges are at or within the planes of the outer ends of, the elements A and B. The member 251s proportioned so that its flanges 31 cooperate with the walls of the sockets 38 to retain the members A and B with their inner ends in abutment.

It is believed that it will be apparent how the flanges 31 cooperating with the sockets 33 retain a or hold the members A and B in the positions just mentioned. Ir. assembling the member 25 in the aligned openings 23 of the bearing elements A and B it is necessary to contract the split member so that the flange 31 on its entering end mayim pass through the openings. In practice the member 25may be readily contracted to have the portions bordering its split 36 lap one over the other. This lapping of the portions bordering the slit 33 materially reduces the diameter of the member 25 so that the flange 31 on its entering end readily passes through the openings 23. When the flange 31 on the advancing or entering end of the member 25 reaches its socket 33 the member 25 is free to expand through its resiliency and returns to a condition where its edges bordering the slit 33 are in cooperation or adjacent relation as illustrated in Fig. 4 of the drawing. The resiliency of the member 25 brings and holds the flanges 31 in effective cooperation with the walls of the sockets 33. In introducing the member 25 in the openings 23 of the elements A and B a flange 31 may be arranged in a socket 33 and the member may be forced inwardly so that the cooperation of the flange with the sloping wall of the socket compresses or contracts the member to the condition described above.

In accordance with the invention the bearing elements A and B and the member 25 have cooperating parts which prevent relative turning between the bearing elements. In the preferred structure illustrated in the drawing a longitu-y dinal groove 43 is cut in the wall of the opening I 23 of each member A and B. This'key' way or groove 43 may extend between the opposing ends of the bearing elements A and B. The retaining member 23 is shaped or bent to have a longitudinally extending rib or key 4| on its periphery. for cooperating with the grooves 43. The key 4| may extend between the flanges 31 or may have I it. ends spaced inwardly from the flanges as illustrated in Fig. 3.1 When the member 2| is inserted in the openings 22 as described above, the

A supporting pin .42 is provided to secure or mount the assembly 0! the cutter C and its hearing on the bit.- The leg l2 and the wing it are provided with aligned downwardly and inwardly inclined openings 42" and 44, respectively. The pin 42 is passed outwardly through the opening 44 and the retaining member 2 5 and its outer portion is threaded in the opening 43. A head 45 is provided on the inner end of the pin 42 ,to bear outwardly against the wing it; The pin 42 extending through the retaining member dependably supports the cutter and bearing as-' sembly on the bit. l

In assembling the cutter C and its bearing, a series 01' balls 24' is first-arranged in a race 23 and a bearing element A-or B is then introduced into the cutter opening 22 to haveits race 34 or 25 cooperate with the balls.- A series of balls 24 is then arranged in the other race 23 and the remaining bearing elementA or B is inserted in the cutter opening 22 to have its race 24 or coopcrate with the balls'24. The retaining member 25 is then contracted and inserted in the openings 22 as described above. 'The member 25 is assembled in the position where its flanges 31 cooperate with the sockets 22 and where its key 4| is received in'the groove 40. The flanges 31 cooperating withthe sockets 3| dependably prevent endwise separation of the bearing elements A and B and the balls 24 cooperating with the opposing pairs of races 32 and 3,4 and 32 and 35' prevent separation oi the cutter C from the bearing elements. Thus the cutter C and its bearing 7 parts are held in assembled relation to constitute a readily handled and transported unit.

When the bearing and cutter unit is to be assembled on the bit it is passed upwardly between a wing it and a leg l2 and the lugs 28 and 2lare brought to positions where they oppose the lower ends l4 and ll of the leg and wing, respectively. In this connection it is to be understood that the key 4| cooperating with the grooves prevents relative turning of the bea ing elements A and B so that the two lugs 29 and it may be simultaneously brought to the desired position and both remain in place during the welding of the lugs to the leg and wing. when the cutter C and its bearing has been positioned between the lug l2 and the wing it the pin 42 is passed through the opening 44 and the member 25 and is threaded-in the opening 43.. The lug 29 may thenbe secured to the end l4 oi the leg I2 by the welding 30 and the lug 2| may be similarly secured to the lower end It of the wing I by the welding 32. v

The retaining member 2! does not in any way interfere with the positioning of the cutter and bearing assembly on the bit; The slit 26 in the member 25 is provided in the upper portions of the openings 22 as described above, so that the slit portions 01 the member 25 are not subjected to the heavy forces transmitted between the pin 42 .andthe bearing elements A and B. When the pin 42 is removed to permit the removal and replacement of the cutter C and the bearing assembly the retaining member 25 remains in holding engagement with the bearing elements A and B so that the utter and its bearing parts are removed as a siggle unit.

Having desc bed only a, typical preferred form and application of my invention I do not wish to be limited or restricted to the specific details herein set forth but wish to reserve to mysell, any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. An assembly or the character described comprising a roller having an opening, tubular bearing elements in the opening, anti-friction partsrotatably supporting theroller on the bearing elements and transmitting end thrusts betweenthe roller and the bearing elements, a tubular retaining member to be arranged'in the bearing elements and having laterally projecting end parts to cooperate with the ends of the bearing elements to hold the elements against axial separation, said retaining member being flexible and split longitudinally from one end to the. other whereby it may be contracted for ready insertion in the bearing elements, and key and groove connections between the member and the bear- 1 ing. elements preventing relative turning between the elements.

- 2. Bearing means for a rotatable roller comprising two tubular bearing elements arranged in end to end relation and having tapered sockets in their outer ends and peripheral ball grooves, balls cooperating with the grooves and the roller to rotatably support the roller, a tubular member for arrangement through the elemerits, and flaring preformed flanges on the opposite ends of the member engaging in said sockets to hold the bearing elements against longitudinal separation, the member being longitudinally split from one end to the other whereby it may be contracted through the engagement of one of said flanges with one of said tapered sockets to have the parts 01' its flanges at the split in overlapping relation whereby the member may be readily introduced into the bearing elements.

3. An assembly to be mounted between spaced supporting parts comprising a roller having an opening, tubular bearing elements in the opening of the roller, balls rotatably supporting the roller on said elements and transmitting end thrusts between the roller and said elements, lugs at the outer ends of the elements to be secured to said parts, a split flexible tubular member arranged in the said elements and having preformed end flanges engaging the ends 01' the elements to hold the elements against axial separation whereby the assembly may be arranged between said parts as a unit, and key connections between the member and the elements preventing relative turning of the said elements whereby the lugs are maintained in the correct relationship to be simultaneously positioned at the lower ends of said parts for attachment thereto.

4. An assembly to be mounted between spaced supporting parts comprising a roller having an opening, tubular bearing elements in the opening of the roller, balls rotatably supporting the roller on said elements and transmitting end thrusts between the roller and said elements,

lugsat the outer ends oi the elements to be sedinal grooves in the interiors of the elements,

and a key on'the member cooperating W161 the grooves to hold the elements'again'st relative turning so that the lugs may be simultaneously located for attachment to the said supporting parts, the grooves and lugs being related so'that the split or the tubular member is at the upper side of the member when the lugs are attached to the lower ends of said parts.

ROBERT W. MAXWELL no 

